// Copyright 2017 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "utils/WGPUHelpers.h"

#include "common/Constants.h"
#include "common/Log.h"

#include "spirv-tools/optimizer.hpp"

#include <cstring>
#include <iomanip>
#include <limits>
#include <mutex>
#include <sstream>

namespace utils {
    wgpu::ShaderModule CreateShaderModuleFromASM(const wgpu::Device& device, const char* source) {
        // Use SPIRV-Tools's C API to assemble the SPIR-V assembly text to binary. Because the types
        // aren't RAII, we don't return directly on success and instead always go through the code
        // path that destroys the SPIRV-Tools objects.
        wgpu::ShaderModule result = nullptr;

        spv_context context = spvContextCreate(SPV_ENV_UNIVERSAL_1_3);
        ASSERT(context != nullptr);

        spv_binary spirv = nullptr;
        spv_diagnostic diagnostic = nullptr;
        if (spvTextToBinary(context, source, strlen(source), &spirv, &diagnostic) == SPV_SUCCESS) {
            ASSERT(spirv != nullptr);
            ASSERT(spirv->wordCount <= std::numeric_limits<uint32_t>::max());

            wgpu::ShaderModuleSPIRVDescriptor spirvDesc;
            spirvDesc.codeSize = static_cast<uint32_t>(spirv->wordCount);
            spirvDesc.code = spirv->code;

            wgpu::ShaderModuleDescriptor descriptor;
            descriptor.nextInChain = &spirvDesc;
            result = device.CreateShaderModule(&descriptor);
        } else {
            ASSERT(diagnostic != nullptr);
            dawn::WarningLog() << "CreateShaderModuleFromASM SPIRV assembly error:"
                               << diagnostic->position.line + 1 << ":"
                               << diagnostic->position.column + 1 << ": " << diagnostic->error;
        }

        spvDiagnosticDestroy(diagnostic);
        spvBinaryDestroy(spirv);
        spvContextDestroy(context);

        return result;
    }

    wgpu::ShaderModule CreateShaderModule(const wgpu::Device& device, const char* source) {
        wgpu::ShaderModuleWGSLDescriptor wgslDesc;
        wgslDesc.source = source;
        wgpu::ShaderModuleDescriptor descriptor;
        descriptor.nextInChain = &wgslDesc;
        return device.CreateShaderModule(&descriptor);
    }

    wgpu::Buffer CreateBufferFromData(const wgpu::Device& device,
                                      const void* data,
                                      uint64_t size,
                                      wgpu::BufferUsage usage) {
        wgpu::BufferDescriptor descriptor;
        descriptor.size = size;
        descriptor.usage = usage | wgpu::BufferUsage::CopyDst;
        wgpu::Buffer buffer = device.CreateBuffer(&descriptor);

        device.GetQueue().WriteBuffer(buffer, 0, data, size);
        return buffer;
    }

    ComboRenderPassDescriptor::ComboRenderPassDescriptor(
        std::initializer_list<wgpu::TextureView> colorAttachmentInfo,
        wgpu::TextureView depthStencil) {
        for (uint32_t i = 0; i < kMaxColorAttachments; ++i) {
            cColorAttachments[i].loadOp = wgpu::LoadOp::Clear;
            cColorAttachments[i].storeOp = wgpu::StoreOp::Store;
            cColorAttachments[i].clearColor = {0.0f, 0.0f, 0.0f, 0.0f};
        }

        cDepthStencilAttachmentInfo.clearDepth = 1.0f;
        cDepthStencilAttachmentInfo.clearStencil = 0;
        cDepthStencilAttachmentInfo.depthLoadOp = wgpu::LoadOp::Clear;
        cDepthStencilAttachmentInfo.depthStoreOp = wgpu::StoreOp::Store;
        cDepthStencilAttachmentInfo.stencilLoadOp = wgpu::LoadOp::Clear;
        cDepthStencilAttachmentInfo.stencilStoreOp = wgpu::StoreOp::Store;

        colorAttachmentCount = static_cast<uint32_t>(colorAttachmentInfo.size());
        uint32_t colorAttachmentIndex = 0;
        for (const wgpu::TextureView& colorAttachment : colorAttachmentInfo) {
            if (colorAttachment.Get() != nullptr) {
                cColorAttachments[colorAttachmentIndex].view = colorAttachment;
            }
            ++colorAttachmentIndex;
        }
        colorAttachments = cColorAttachments.data();

        if (depthStencil.Get() != nullptr) {
            cDepthStencilAttachmentInfo.view = depthStencil;
            depthStencilAttachment = &cDepthStencilAttachmentInfo;
        } else {
            depthStencilAttachment = nullptr;
        }
    }

    ComboRenderPassDescriptor::ComboRenderPassDescriptor(const ComboRenderPassDescriptor& other) {
        *this = other;
    }

    const ComboRenderPassDescriptor& ComboRenderPassDescriptor::operator=(
        const ComboRenderPassDescriptor& otherRenderPass) {
        cDepthStencilAttachmentInfo = otherRenderPass.cDepthStencilAttachmentInfo;
        cColorAttachments = otherRenderPass.cColorAttachments;
        colorAttachmentCount = otherRenderPass.colorAttachmentCount;

        colorAttachments = cColorAttachments.data();

        if (otherRenderPass.depthStencilAttachment != nullptr) {
            // Assign desc.depthStencilAttachment to this->depthStencilAttachmentInfo;
            depthStencilAttachment = &cDepthStencilAttachmentInfo;
        } else {
            depthStencilAttachment = nullptr;
        }

        return *this;
    }

    BasicRenderPass::BasicRenderPass()
        : width(0),
          height(0),
          color(nullptr),
          colorFormat(wgpu::TextureFormat::RGBA8Unorm),
          renderPassInfo({}) {
    }

    BasicRenderPass::BasicRenderPass(uint32_t texWidth,
                                     uint32_t texHeight,
                                     wgpu::Texture colorAttachment,
                                     wgpu::TextureFormat textureFormat)
        : width(texWidth),
          height(texHeight),
          color(colorAttachment),
          colorFormat(textureFormat),
          renderPassInfo({colorAttachment.CreateView()}) {
    }

    BasicRenderPass CreateBasicRenderPass(const wgpu::Device& device,
                                          uint32_t width,
                                          uint32_t height) {
        DAWN_ASSERT(width > 0 && height > 0);

        wgpu::TextureDescriptor descriptor;
        descriptor.dimension = wgpu::TextureDimension::e2D;
        descriptor.size.width = width;
        descriptor.size.height = height;
        descriptor.size.depthOrArrayLayers = 1;
        descriptor.sampleCount = 1;
        descriptor.format = BasicRenderPass::kDefaultColorFormat;
        descriptor.mipLevelCount = 1;
        descriptor.usage = wgpu::TextureUsage::RenderAttachment | wgpu::TextureUsage::CopySrc;
        wgpu::Texture color = device.CreateTexture(&descriptor);

        return BasicRenderPass(width, height, color);
    }

    wgpu::ImageCopyBuffer CreateImageCopyBuffer(wgpu::Buffer buffer,
                                                uint64_t offset,
                                                uint32_t bytesPerRow,
                                                uint32_t rowsPerImage) {
        wgpu::ImageCopyBuffer imageCopyBuffer = {};
        imageCopyBuffer.buffer = buffer;
        imageCopyBuffer.layout = CreateTextureDataLayout(offset, bytesPerRow, rowsPerImage);

        return imageCopyBuffer;
    }

    wgpu::ImageCopyTexture CreateImageCopyTexture(wgpu::Texture texture,
                                                  uint32_t mipLevel,
                                                  wgpu::Origin3D origin,
                                                  wgpu::TextureAspect aspect) {
        wgpu::ImageCopyTexture imageCopyTexture;
        imageCopyTexture.texture = texture;
        imageCopyTexture.mipLevel = mipLevel;
        imageCopyTexture.origin = origin;
        imageCopyTexture.aspect = aspect;

        return imageCopyTexture;
    }

    wgpu::TextureDataLayout CreateTextureDataLayout(uint64_t offset,
                                                    uint32_t bytesPerRow,
                                                    uint32_t rowsPerImage) {
        wgpu::TextureDataLayout textureDataLayout;
        textureDataLayout.offset = offset;
        textureDataLayout.bytesPerRow = bytesPerRow;
        textureDataLayout.rowsPerImage = rowsPerImage;

        return textureDataLayout;
    }

    wgpu::PipelineLayout MakeBasicPipelineLayout(const wgpu::Device& device,
                                                 const wgpu::BindGroupLayout* bindGroupLayout) {
        wgpu::PipelineLayoutDescriptor descriptor;
        if (bindGroupLayout != nullptr) {
            descriptor.bindGroupLayoutCount = 1;
            descriptor.bindGroupLayouts = bindGroupLayout;
        } else {
            descriptor.bindGroupLayoutCount = 0;
            descriptor.bindGroupLayouts = nullptr;
        }
        return device.CreatePipelineLayout(&descriptor);
    }

    wgpu::PipelineLayout MakePipelineLayout(const wgpu::Device& device,
                                            std::vector<wgpu::BindGroupLayout> bgls) {
        wgpu::PipelineLayoutDescriptor descriptor;
        descriptor.bindGroupLayoutCount = uint32_t(bgls.size());
        descriptor.bindGroupLayouts = bgls.data();
        return device.CreatePipelineLayout(&descriptor);
    }

    wgpu::BindGroupLayout MakeBindGroupLayout(
        const wgpu::Device& device,
        std::initializer_list<BindingLayoutEntryInitializationHelper> entriesInitializer) {
        std::vector<wgpu::BindGroupLayoutEntry> entries;
        for (const BindingLayoutEntryInitializationHelper& entry : entriesInitializer) {
            entries.push_back(entry);
        }

        wgpu::BindGroupLayoutDescriptor descriptor;
        descriptor.entryCount = static_cast<uint32_t>(entries.size());
        descriptor.entries = entries.data();
        return device.CreateBindGroupLayout(&descriptor);
    }

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        uint32_t entryBinding,
        wgpu::ShaderStage entryVisibility,
        wgpu::BufferBindingType bufferType,
        bool bufferHasDynamicOffset,
        uint64_t bufferMinBindingSize) {
        binding = entryBinding;
        visibility = entryVisibility;
        buffer.type = bufferType;
        buffer.hasDynamicOffset = bufferHasDynamicOffset;
        buffer.minBindingSize = bufferMinBindingSize;
    }

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        uint32_t entryBinding,
        wgpu::ShaderStage entryVisibility,
        wgpu::SamplerBindingType samplerType) {
        binding = entryBinding;
        visibility = entryVisibility;
        sampler.type = samplerType;
    }

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        uint32_t entryBinding,
        wgpu::ShaderStage entryVisibility,
        wgpu::TextureSampleType textureSampleType,
        wgpu::TextureViewDimension textureViewDimension,
        bool textureMultisampled) {
        binding = entryBinding;
        visibility = entryVisibility;
        texture.sampleType = textureSampleType;
        texture.viewDimension = textureViewDimension;
        texture.multisampled = textureMultisampled;
    }

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        uint32_t entryBinding,
        wgpu::ShaderStage entryVisibility,
        wgpu::StorageTextureAccess storageTextureAccess,
        wgpu::TextureFormat format,
        wgpu::TextureViewDimension textureViewDimension) {
        binding = entryBinding;
        visibility = entryVisibility;
        storageTexture.access = storageTextureAccess;
        storageTexture.format = format;
        storageTexture.viewDimension = textureViewDimension;
    }

    // ExternalTextureBindingLayout never contains data, so just make one that can be reused instead
    // of declaring a new one every time it's needed.
    wgpu::ExternalTextureBindingLayout kExternalTextureBindingLayout = {};

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        uint32_t entryBinding,
        wgpu::ShaderStage entryVisibility,
        wgpu::ExternalTextureBindingLayout* bindingLayout) {
        binding = entryBinding;
        visibility = entryVisibility;
        nextInChain = bindingLayout;
    }

    BindingLayoutEntryInitializationHelper::BindingLayoutEntryInitializationHelper(
        const wgpu::BindGroupLayoutEntry& entry)
        : wgpu::BindGroupLayoutEntry(entry) {
    }

    BindingInitializationHelper::BindingInitializationHelper(uint32_t binding,
                                                             const wgpu::Sampler& sampler)
        : binding(binding), sampler(sampler) {
    }

    BindingInitializationHelper::BindingInitializationHelper(uint32_t binding,
                                                             const wgpu::TextureView& textureView)
        : binding(binding), textureView(textureView) {
    }

    BindingInitializationHelper::BindingInitializationHelper(
        uint32_t binding,
        const wgpu::ExternalTexture& externalTexture)
        : binding(binding) {
        externalTextureBindingEntry.externalTexture = externalTexture;
    }

    BindingInitializationHelper::BindingInitializationHelper(uint32_t binding,
                                                             const wgpu::Buffer& buffer,
                                                             uint64_t offset,
                                                             uint64_t size)
        : binding(binding), buffer(buffer), offset(offset), size(size) {
    }

    wgpu::BindGroupEntry BindingInitializationHelper::GetAsBinding() const {
        wgpu::BindGroupEntry result;

        result.binding = binding;
        result.sampler = sampler;
        result.textureView = textureView;
        result.buffer = buffer;
        result.offset = offset;
        result.size = size;
        if (externalTextureBindingEntry.externalTexture != nullptr) {
            result.nextInChain = &externalTextureBindingEntry;
        }

        return result;
    }

    wgpu::BindGroup MakeBindGroup(
        const wgpu::Device& device,
        const wgpu::BindGroupLayout& layout,
        std::initializer_list<BindingInitializationHelper> entriesInitializer) {
        std::vector<wgpu::BindGroupEntry> entries;
        for (const BindingInitializationHelper& helper : entriesInitializer) {
            entries.push_back(helper.GetAsBinding());
        }

        wgpu::BindGroupDescriptor descriptor;
        descriptor.layout = layout;
        descriptor.entryCount = entries.size();
        descriptor.entries = entries.data();

        return device.CreateBindGroup(&descriptor);
    }

}  // namespace utils